I-joists are increasingly utilized structural elements in architectural constructions and the like. I-joists are beams that have an I like profile to provide maximum stiffness and strength with a minimum of weight. I-joists are commonly fabricated in a number of dimensional standards from wood and wood like materials.
Architectural constructions often require the cutting of holes into the web portion of the I-joist to lay pipes, electrical lines and the like across one or more installed I-joist. There exist a number of standards for maximum hole sizes that may be cut into the web portion. Of primary concern is thereby a remaining offset between the web hole and the horizontal top and bottom portion of the I-joist in order to keep the I-joists buckling tendency within safe limits. Therefore there exists a need for a hole cutting apparatus that provides spacing between adjacent sticking out structures while cutting the hole. The present invention addresses this need.
The cutting of large diameter holes at the construction site is mainly accomplished by hand held power tools in which the cutting apparatus is rotatable held. Therefore, for cutting large diameter holes there exists also a need for a cutting apparatus that provides cutting action with minimum friction, reduced peak torque and safe operation without pronounced or sharp features extending beyond the circumference of the rotating apparatus. The present invention addresses also these needs.